我们的设计中VIN的输入时间会比Vbias晚,我想知道如果PG用VBIAS来上拉的话 会有什么问题吗?在EN未使能时,PG会一直保持为低吗?
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There is no issue if PG uses VBIAS to pullup, as long as VBias is guaranteed high whenever the device is properly regulating (the requirement for PG to be pulled high). Technically the TPS7A84A can operate without using the VBias rail so I thought I'd note it. PG will remain low when EN is not enabled as long as Vbias>=0.
即使VIN不符合通电电压,PG也将为零。它的设计目的是在UVLO、dropout和关机时输出0,而不会出现不受控制的状态。只有当FB上的比较器被触发时,它才应该是Hi-Z(在您的情况下拉高到VBIAS)。